1. Field of the Invention
This invention relates to an improved lung graft preservative composition and an improved method for viable preservation of the lung graft for transplantation. More particularly, this invention relates to a lung graft preservative composition comprising an ascorbyl tocopheryl phosphate compound or a pharmacologically acceptable salt thereof and a method for viable preservation of a lung graft which comprises using said compound or salt.
2. Description of the Prior Art
For a successful organ transplantation, the organ resected from a donor must be kept functionally intact for a certain time period. Each kind of organ has its own characteristics and, hence, demands a unique protocol for viable storage. However, the preservation principles applicable to all organs in common are metabolic inhibition or metabolic maintenance.
For the viable preservation of the lung isolated For transplantation, (1) the donor core cooling method employing an extracorporeal circuit, (2) the method comprising flushing the pulmonary vascular bed with a perfusate from the pulmonary artery and, then preserving the lung under cooling, (3) the simple topical cooling method, and (4) the heart-lung autoperfusion method are known. Generally, however, for an effective cooling of the lung prior to resection, the method comprising flushing the lung from the pulmonary artery, immediately resecting the lung and immersing It in a preservative solution such as Euro-Collins solution is frequently employed.
However, it has been pointed out that these techniques have the drawback that on warm blood reperfusion of the lung after storage, pulmonary edema develops for some reasons or others so that the depression of the gas exchange function of the lung cannot be adequately prevented. Therefore, a more improved preservative for use in lung transplantation has been demanded and earnest research and development are in progress.
In the course of their ceaseless research into the pharmacology of ascorbyl tocopheryl phosphate compounds, the inventors of this invention discovered that these compounds are useful for the viable preservation of the lung isolated for transplantation. This discovery was followed by further studies which have resulted in the development of this invention.